温度参数对铌微合金高强度结构钢组织性能的影响  

Effect of Temperature Parameters on Microstructure and Mechanical Properties of Nb Micro-Alloyed High Strength Structural Steel

作　　者：杜海军[1] 赵德文[1] 杜林秀[1] 刘相华[1] 赵胜国 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110004 [2]河北普阳钢铁有限公司,河北邯郸056001

出　　处：《钢铁研究学报》2010年第6期35-39,共5页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(50474015)

摘　　要：通过控轧控冷试验,力学性能检验和组织的光学显微观察,研究了温度参数对铌微合金钢组织性能的影响。结果表明:两阶段控轧及控冷所获晶粒尺寸明显小于常规轧制+快速冷却的晶粒尺寸;随冷却速率的增大或终冷温度的降低或精轧开轧温度的降低,试验钢晶粒细化,混晶程度加重,强度增大,塑性降低;精轧低温开轧利于韧性提高;铁素体混晶可能源于因铸坯中Nb(C,N)的不均匀分布造成的原始奥氏体混晶,粗轧大压缩比轧制可以消除这种混晶现象。Control rolling and cooling experiments were done in laboratory.The effects of temperature parameters,consisting of rolling temperature region,the start temperature of finish rolling,the cooling rate and the final cooling temperature on the final microstructure and mechanical properties of Nb-microalloyed steel were studied by tensile and charpy impact tests and optical microscopy.The results show that the finer grain can be obtained by two-stage controlled rolling and cooling compared with conventional rolling and rapid cooling;with increasing the cooling rate,or decreasing the start temperature of finish rolling or lowering the final cooling temperature,the grains size are refined,content of the mixed grains is aggravated,the strength increased and the plasticity decreased,the lower rolling temperature of finish rolling is helpful to improve the low temperature toughness;the mixed ferrite grains arise from mixed original austenite grains which may be due to inhomogeneous distribution of Nb（C,N） precipitates in casting slab,rolling with larger compression ratio in coarse rolling can eliminate the mixed grains.

关 键 词：温度参数 控轧控冷 铌微合金钢 混晶 组织性能 

分 类 号：TG335[金属学及工艺—金属压力加工] TG142.1[一般工业技术—材料科学与工程]